# Is there a built-in Python function to generate 100 numbers from 0 to 1?

## Question:

I am looking for something like `range`

, but one that will allow me to specify the start and the end value, along with how many numbers I need in the collection which I want to use in a similar fashion `range`

is used in `for loops`

.

## Answers:

Python doesn’t have a floating point range function but you can simulate one easily with a list comprehension:

```
>>> lo = 2.0
>>> hi = 12.0
>>> n = 20
>>> [(hi - lo) / n * i + lo for i in range(n)]
[2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5]
```

Note, in numeric applications, people typically want to include both endpoints rather than have a half-open interval like Python’s built-in *range()* function. If you need both end-points you can easily add that by changing `range(n)`

to `range(n+1)`

.

Also, consider using numpy which has tools like *arange()* and *linspace()* already built in.

You can still use `range`

, you know. You just need to start out big, then divide:

```
for x in range(100):
print x/100.0
```

If you want to include the endpoint:

```
for x in range(101):
print x/100.0
```

There is a special function in numpy to do this: `linspace`

. Ofcourse you will have to install numpy first. You can find more about it here.

No, there is no built-in function to do what you want. But, you can always define your own `range`

:

```
def my_range(start, end, how_many):
incr = float(end - start)/how_many
return [start + i*incr for i in range(how_many)]
```

And you can using in a for-loop in the same way you would use `range`

:

```
>>> for i in my_range(0, 1, 10):
... print i
...
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
```

**EDIT:** If you want both `start`

and `end`

to be part of the result, your `my_range`

function would be:

```
def my_range(start, end, how_many):
incr = float(end - start)/(how_many - 1)
return [start + i*incr for i in range(how_many-1)] + [end]
```

And in your for-loop:

```
>>> for i in my_range(0, 1, 10):
... print i
...
0.0
0.111111111111
0.222222222222
0.333333333333
0.444444444444
0.555555555556
0.666666666667
0.777777777778
0.888888888889
1
```